Coated article including titanium oxycarbide and method of making same

ABSTRACT

A coated article is provided which includes a layer including titanium oxycarbide. In order to form the coated article, a layer of titanium oxide is deposited on a substrate by sputtering or the like. After sputtering of the layer including titanium oxide, an ion beam source(s) is used to implant at least carbon ions into the titanium oxide. When implanting, the carbon ions have sufficient ion energy so as to knock off oxygen (O) from TiO x  molecules so as to enable a substantially continuous layer comprising titanium oxycarbide to form near a surface of the previously sputtered layer.

This application relates to a coated article including a layercomprising titanium oxycarbide, and a method of making the same. Incertain example embodiments, a layer of titanium oxide (e.g., TiO_(x),where x is from 1 to 3, preferably about 2) is sputter deposited on asubstrate; and thereafter an ion source(s) using a high voltage is usedto implant carbon (C) ions with high energy into the titanium oxide soas to form a layer comprising titanium oxycarbide.

BACKGROUND OF THE INVENTION

Contact angle θ in general is discussed in U.S. Pat. Nos. 6,303,225 and6,461,731, the disclosures of which are hereby incorporated herein byreference. In certain instances, high contact angles are desired, whilein other instances low contact angles are desired. The desired contactangle depends upon the situation in which an intended product is to beused.

It is known in the art to coat a glass substrate with a layer oftitanium oxide (e.g., TiO₂, or other stoichiometry). A layer of titaniumoxide, if provided as the outermost layer on a glass substrate, canachieve a rather low contact angle θ with a sessile drop of water afterlengthy exposure to ultraviolet (UV) radiation and water.

However, titanium oxide layers are problematic with respect todurability. For example, the scratch resistance of a titanium oxidelayer is not that much better than that of glass. As a result, coatedarticles with an exposed layer of titanium oxide are highly susceptibleto damage (e.g., scratching) during transport and the like, and areproblematic in this respect.

In view of the above, it is apparent that there exists a need in the artfor a coated article that is more durable (e.g., scratch resistant) thanis pure titanium oxide. In certain example instances, a low contactangle θ may also be desired.

BRIEF SUMMARY OF EXAMPLE EMBODIMENTS

According to certain example embodiments of this invention, a coatedarticle is provided which includes a layer comprising titaniumoxycarbide and/or titanium carbide. In order to form the coated article,a layer comprising titanium oxide (e.g., TiO_(x), where x is from 1 to3, preferably about 2) is deposited on a substrate by sputtering (e.g.,magnetron sputtering) or any other suitable deposition technique. Otherlayer(s) may or may not be provided between the substrate and the layercomprising titanium oxide in different embodiments of this invention.After sputtering of the layer comprising TiO_(x), an ion beam source(s)is used to implant at least carbon ions into the TiO_(x). Whenimplanting into the TiO_(x) inclusive layer, the carbon ions havesufficient ion energy to penetrate the surface of the layer and knockoff oxygen (O) atoms from TiO_(x) molecules so as to enable asubstantially continuous layer comprising titanium oxycarbide to formnear a surface of the previously sputtered layer. In embodiments wherethe sputtered TiO_(x) layer is sufficiently thick, the layer comprisingtitanium oxycarbide may be formed over a layer of TiO_(x) which wasoriginally a lower portion of the originally sputtered TiO_(x) layer.

A relatively high voltage is required in the ion source(s) in order toprovide sufficient energy for the carbon ions from the ion source to:(a) penetrate the surface and implant into the sputtered TiO_(x) layer,(b) knock off oxygen from TiO_(x) molecules, and (c) carry out (a) and(b) to an extent sufficient so that a substantially continuous layer oftitanium oxycarbide can be formed. In order to achieve sufficient energyin this respect, according to certain example embodiments of thisinvention the ion source(s) uses an anode-cathode voltage of at leastabout 800 V, more preferably of at least about 1,500 V, even morepreferably of at least about 2,000V, and still more preferably of atleast about 2,500 V. For purposes of example only, in the case where theC ions are formed using acetylene (C₂H₂) as a feedstock gas in an ionsource, the aforesaid ion source voltages translate into respective ionenergies of at least about 200 eV per C ion, more preferably at leastabout 375 eV per C ion, even more preferably at least about 500 eV per Cion, and still more preferably of at least about 625 eV per C ion.

In certain example embodiments, C ions are implanted deep enough intothe sputtered TiO_(x) layer so as to enable a substantially continuouslayer comprising titanium oxycarbide to form at least at a top portionthereof. This layer comprising titanium oxycarbide may include TiO, TiC,TiOC, OC, CC, CH, and/or combinations thereof. In certain exampleembodiments, at least some C ions (or C atoms) are implanted into thesputtered layer to a depth “d” of at least 25 Å below the top surface ofthe sputtered layer (more preferably at least 50 Å, even more preferablyat least 100 Å).

The coated article made, as explained above, to include a layercomprising titanium oxycarbide has improved scratch resistance comparedto that of a purely titanium oxide layer. Moreover, in certain exampleembodiments, the use of C implantation enables certain contact angle θcharacteristics to be improved. For example, the resulting coatedarticle may be capable of achieving lower contact angles θ (initial, orafter UV/water exposure) than a layer of pure amorphous diamond-likecarbon (DLC) and/or a layer of pure titanium oxide. The resulting coatedarticle may also be capable of maintaining a low contact angle(s) θ fora longer period of time than a layer of titanium oxide. Thus, it can beseen that the implantation of C ions/atoms into the layer comprisingtitanium oxide is advantageous in several respects.

Optionally, in addition to the C ions which are implanted into the layercomprising titanium oxide to form the titanium oxycarbide, further ionbeam deposition of carbon using high ion energy may take place over thetitanium oxycarbide in certain example embodiments so that a thin layercomprising amorphous diamond-like carbon (DLC) with a large amount ofsp³ carbon-carbon bonds (e.g., at least 40% such bonds, more preferablyat least 50% such bonds) may be formed over the oxycarbide. Thisadditional DLC layer may be from 0 to 100 Å thick in certain exampleembodiments of this invention, more preferably from 1 to 40 Å thick, andmost preferably from about 1 to 30 Å thick. This optional DLC layer mayor may not be hydrogenated (e.g., from about 1–25% H, more preferablyfrom about 3–18% H) or include other dopants in different embodiments ofthis invention, and may have a density of at least 2.4 gms/cm³ incertain example instances. This DLC inclusive layer may serve to improvedurability in certain example embodiments of this invention.

In certain example embodiments of this invention, there is provided amethod of making a coated article, the method comprising: providing aglass substrate; sputtering a layer comprising titanium oxide TiO_(x)(where x is from 1 to 3) on the substrate, thereby forming a sputteredlayer; and utilizing at least one ion source using anode-cathode voltageof at least about 1,500 V to cause at least carbon ions to be directedtoward the sputtered layer comprising titanium oxide so that at leastsome of the carbon ions are implanted into the sputtered layer to adepth of at least 25 Å below a surface of the sputtered layer.

In other example embodiments of this invention, there is provided amethod of making a coated article, the method comprising: providing asubstrate; forming a layer comprising a metal oxide on the substrate;and directing at least carbon ions toward the layer comprising the metaloxide, at least some of the carbon ions having an ion energy of at least200 eV per carbon ion so that at least some of the carbon ions implantin the layer thereby forming a layer comprising an oxycarbide.

In other example embodiments of this invention, there is provided acoated article comprising a coating supported by a substrate, thecoating comprising: a sputtered layer comprising a metal oxide, and atleast carbon atoms which are ion beam implanted in the sputtered layercomprising the metal oxide, at least some of the carbon ions beingimplanted to a depth of at least 25 Å below a surface of the sputteredlayer, thereby forming a layer comprising an oxycarbide.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic partial cross sectional view illustrating atechnique for making a coated article according to an example embodimentof this invention.

FIG. 2 is a flowchart illustrating certain steps performed in making thearticle of FIG. 1 according to an example embodiment of this invention.

FIG. 3 is a sectional view of an example ion source which may be used toimplant carbon ions into the originally sputtered titanium oxideinclusive layer of FIGS. 1–2 according to an example embodiment of thisinvention.

FIG. 4 is a perspective view of the ion source of FIG. 3.

FIG. 5 is an XPS (X-ray Photoelectron Spectroscopy) graph illustratingthe elements/components present in atomic amounts throughout thethickness of the layer system of Example 1 at a first location on thesubstrate.

FIG. 6 is an XPS graph illustrating the elements/components present inatomic amounts throughout the thickness of the layer system of Example 1at a second location on the substrate (different than the first locationmeasured in FIG. 5).

FIG. 7 is a time vs. contact angle θ graph comparing a sputtered layerof only TiO₂ to sputtered TiO₂ implanted with and/or covered withdifferent amounts of C.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

Certain embodiments of the instant invention relate to a coated articlewhich includes a layer comprising titanium oxycarbide. In order to formthe coated article in certain example embodiments, a layer of titaniumoxide (e.g., TiO_(x), where x is from 1 to 3, more preferably from 1.5to 2.5, and most preferably about 2) is deposited on a substrate bysputtering (e.g., magnetron sputtering) or via any other suitabledeposition technique. Other layer(s) may or may not be provided betweenthe substrate and the titanium oxide in different embodiments of thisinvention. After sputtering of the layer comprising TiO_(x), at leastone ion beam source is used to implant carbon (C) ions into the TiO_(x).When implanting into the TiO_(x) layer, the carbon ions have sufficiention energy so as to penetrate the surface of the sputtered layer, andknock off oxygen (O) from TiO_(x) molecules so as to enable asubstantially continuous layer comprising titanium oxycarbide to formnear a surface of the previously sputtered layer. In embodiments wherethe sputtered TiO_(x) layer is sufficiently thick, the layer comprisingtitanium oxycarbide may be formed over a layer of TiO_(x) which wasoriginally a lower portion of the originally sputtered TiO_(x) layer.

The coated article including at least one substantially continuous layercomprising titanium oxycarbide has improved scratch resistance comparedto that of a purely titanium oxide layer. Moreover, in certain exampleembodiments the use of the C implantation enables certain contact angleθ characteristics to be improved. For example, it has been found thatthe resulting coated article may be capable of achieving lower contactangles θ (initial, or after UV/water exposure) than would a layer ofpure amorphous diamond-like carbon (DLC) and/or a layer of pure TiO₂.Surprisingly, the resulting coated article may also be capable ofmaintaining a low contact angle(s) θ for a longer period of time thanwould a layer of only titanium oxide. Thus, it can be seen that theimplantation of C ions/atoms into the layer comprising titanium oxide isadvantageous in several significant respects.

Coated articles herein comprising an oxycarbide, may be used in variouscommercial applications, including but not limited to insulating glass(IG) window units, vehicle windows, architectural windows, furnitureapplications, and/or the like.

FIG. 1 is a cross sectional view of a coated article being formedaccording to an example embodiment of this invention, whereas FIG. 2sets forth steps that are carried out in making the coated article ofFIG. 1. Referring to FIGS. 1–2, a substrate (e.g., glass substrate whichmay or may not include other layers) is provided (see step A in FIG. 2).An amorphous layer 3 of or including titanium oxide (TiO_(x)) is thendeposited by sputtering on the substrate (see step B in FIG. 2). Thesputtered titanium oxide of layer 3 may or may not be doped with otherelements in different embodiments of this invention. Layer 3 may be fromabout 50 to 1,000 Å thick in certain example embodiments of thisinvention, more preferably from about 50 to 500 Å thick. After theTiO_(x) inclusive layer 3 has been sputtered onto substrate, the coatedarticle is moved in direction 5 as shown in FIG. 1 relative to at leastone ion source 25. At least one gas including carbon (e.g., ahydrocarbon gas such as C₂H₂ or the like) is fed through or used in theion source(s) so that the ion source(s) 25 causes an ion beam includingcarbon (C) ions to be emitted toward the TiO_(x) inclusive layer 3 (seestep C in FIG. 2). The C ions in the ion beam are provided withsufficient energy so that they can implant into the TiO_(x) inclusivelayer 3 as shown in FIG. 1. In FIG. 1, the dots illustrated in layer 3represent C ions/atoms that have implanted into the sputtered layer 3;and the far right-hand portion of the layer 3 in FIG. 1 has no implanteddots because that portion of the coated article has not yet passed underthe ion source. It is noted that the ion beam from source 25 may befocused, diffused, or collimated in different embodiments of thisinvention.

The implantation of C ions/atoms into the sputtered TiO_(x) inclusivelayer 3 causes a layer comprising titanium oxycarbide 3 b to be formedat least proximate the surface of the layer as shown in FIG. 1 (see alsostep D in FIG. 2). This implantation of C ions/atoms into layer 3 causesthe durability of the resulting layer to significantly improve relativeto that of layer 3 before the C ions/atoms were implanted. For example,scratch resistant is significantly improved.

Moreover, it has surprisingly been found that the presence of theimplanted carbon in the layer 3 enables the resulting amorphous layer'scontact angle θ to be fairly low in certain instances relative to puretitanium oxide. For example, FIG. 7 illustrates that the implanted layer3 can realize a lower initial contact angle θ than can a layer of onlyamorphous titanium oxide. Thus, one does not necessarily needmicrocrystalline TiO₂ (anatase or rutile) to induce low contact anglesin a titanium oxide inclusive layer. Moreover, it has surprisingly beenfound that once the C ions/atoms have been implanted in layer 3, and alow contact angle θ has been achieved, the layer's ability to maintain alow contact angle(s) θ over time is significantly improved compared tothe situation where the C ions/atoms were not implanted (see FIG. 7).Yet another surprising aspect of certain example embodiments of thisinvention is that the implantation of the C ions/atoms into layer 3enables the implanted layer to realize hydrophilic behavior (low contactangle(s)) in the presence of green visible light without necessarilyneeding UV to induce lower contact angles). In other words, visiblegreen light for example may cause the contact angle of the implantedlayer to decrease which is advantageous in many commercial situations.

In certain example embodiments of this invention, the layer comprisingtitanium oxycarbide has a contact angle θ of no greater than about 20degrees, more preferably no greater than about 15 degrees. This contactangle may be either an initial contact angle, or after exposure to UVradiation and water (QUV) for at least 50 hours. The QUV exposure isknown in the art.

When implanting into the TiO_(x) layer, the carbon ions have sufficiention energy so as to knock off oxygen (O) from TiO_(x) molecules so as toenable a substantially continuous layer comprising titanium oxycarbide 3b to form near a surface of the previously sputtered layer as shown inFIG. 1. FIG. 1 also illustrates an embodiment where the sputteredTiO_(x) layer 3 was sufficiently thick so that the layer comprisingtitanium oxycarbide 3 b (in the area of the implanted dots shown inFIG. 1) may be formed over a layer of TiO_(x) 3 a which was originally alower portion 3 a of the originally sputtered TiO_(x) layer. In certainexample embodiments, the titanium oxycarbide layer 3 b may becharacterized at least in part by TiO_(x)C_(y), where x/y is from 0.5 to1.5.

It is also believed that the implantation of the C ions/atoms into thelayer 3 as shown in FIG. 1 can cause a heterojunction to occur betweenresulting layers 3 a and 3 b. This heterojunction is formed at theinterface between layers 3 a and 3 b (or alternatively at the interfacebetween semiconductive layer 3 b and an overlying semiconductive layercomprising DLC), these layers having different bandgaps (TiO_(x) isabout 3.2 eV+/− about 0.1, and the DLC may have a bandgap of about 1.9to 2.2 eV). Under chemical equilibrium conditions, the fermi levels arealigned in the two materials, so that band bending may occur. This bandbending creates an internal field at the heterojunction. Chargeaccumulates at the interface. It is believed that when incident light(e.g., visible green light) hits this charge at the heterojunction,electron hole pairs form and cause contact angle θ to decrease.

A relatively high voltage is required in the ion source(s) 25 in orderto provide sufficient energy for the carbon ions in the beam from theion source to: (a) implant into the sputtered TiO_(x) layer 3, (b) knockoff oxygen from TiO_(x) molecules, and (c) carry out (a) and (b) to anextent sufficient so that a substantially continuous layer of titaniumoxycarbide 3 b can be formed. In order to achieve sufficient energy inthis respect, according to certain example embodiments of this inventionthe ion source(s) 25 uses an anode-cathode voltage of at least about 800V, more preferably at least about 1,500 V, even more preferably at leastabout 2,000V, and still more preferably at least about 2,500 V. Even asource voltage of at least about 3,500 V may be used in certaininstances.

The aforesaid “voltage” (or accelerating voltage) referred to which isused in the ion source(s) 25 to cause implantation of the C ions/atomsin layer 3, is the voltage between the anode and the cathode of the ionsource 25. As is known in the art, “ion energy” is related to thisanode/cathode “voltage” but is different therefrom. The molecularfragment ion energy is one half (½) of the accelerating voltage formolecular acetylene (C₂H₂) for example. Thus, the molecular fragment ionenergy, given a voltage of 2,000 V would be 2,000/2=1,000 V. Moreover,in the case of C ions formed from acetylene (C₂H₂) used as a feedstockgas in the ion source, there are two carbon atoms per molecularfragment. Thus, the energy per carbon ion is the molecular fragment ionenergy divided by 2 in this case where C₂H₂ is used as the feedstock gasto form the C ions in the beam. In other words, for purposes of exampleonly, in the case where the C ions are formed using C₂H₂ as thefeedstock gas in the ion source 25, ion source voltages (i.e., at leastabout 800 V, 1,500 V, 2,000 V and/or 2,500 V as explained above)translate into ion energies of at least about 200 eV per C ion, morepreferably at least about 375 eV per C ion, even more preferably atleast about 500 eV per C ion, and still more preferably at least about625 eV per C ion.

In certain embodiments of this invention, it is important that one ormore of the aforesaid ion source voltages and/or ion energies be used.This is because, if too low of an ion energy (or voltage in the ionsource 25) is used (e.g., 75 eV per C ion is too low), C ionimplantation and/or formation of a continuous layer comprising titaniumoxycarbide cannot be achieved.

It will be recognized that when a hydrocarbon gas such as C₂H₂ is usedas the feedstock gas in the source 25, the ions in the resulting beamwill include both C ions and H ions. Thus, the titanium oxycarbide layer3 b may be doped with H in certain embodiments of this invention. Incertain example embodiments, the layer 3 b may include from 0 to 20% H,more preferably from about 1 to 18% H, and even more preferably fromabout 5 to 15% H. Other materials may also be present in layers 3 a, 3 bin certain instances, as shown in the XPS graphs discussed herein.

In certain embodiments of this invention, C ions are implanted deepenough into the sputtered TiO_(x) layer 3 so as to enable asubstantially continuous layer comprising titanium oxycarbide 3 b toform at least proximate a top portion thereof. In certain exampleembodiments, at least some C ions (and/or C atoms) are implanted intothe sputtered layer 3 to a depth “d” of at least 25 Å below the topsurface of the sputtered layer (more preferably at least 50 Å, even morepreferably at least 100 Å). Insufficient implantation may contribute tonon-enhancement of durability, or the like, or very quick wearing off ofthe same.

In certain example embodiments of this invention, the ion source(s) 25may be operated so as to only emit enough C ions toward layer 3 so as tocause C ion/atom implantation in layer 3 as shown in FIG. 1, but not tocause a layer of amorphous DLC (e.g., ta-C or ta-C:H) to form over thetitanium oxycarbide layer 3 b. Alternatively, in other embodiments ofthis invention, the source(s) 25 is operated so as to cause a thin layer(not shown) comprising amorphous DLC (e.g., ta-C or ta-C:H) to form overthe titanium oxycarbide layer 3 b. Example characteristics of such DLClayers are discussed in U.S. Pat. No. 6,261,693, hereby incorporatedherein by reference. This thin DLC layer may be from about 1–30 Å thickin certain example embodiments, more preferably from about 1–20 Å thick.It is noted that other layers may also be provided over the oxycarbidein certain instances. Moreover, this very thin DLC inclusive layer mayin certain embodiments be sacrificial in that it is designed so that itmay wear away (i.e., disappear) over time. Thus, for example, such athin layer comprising DLC may be used to protect the coated article fromscratching or the like during shipping, process, or the like, and thenwear off over time so as to expose the layer comprising titaniumoxycarbide 3 b which may be characterized by a more desirable lowcontact angle and/or good durability. It is also noted that in certainexample embodiments, the titanium oxycarbide may be designed to besacrificial, so that it wears away over time after its job of protectingthe coating from scratching or the like during shipment, processing, orthe like, has been fulfilled.

Optionally, this overlying layer comprising DLC may be even thicker than30 Å in certain example instances. Such overlying DLC inclusive layer(s)herein may include a large amount of sp carbon-carbon bonds (e.g., atleast 40% of C—C bonds in the layer may be such bonds, more preferablyat least 50%), may or may not be hydrogenated (e.g., from about 1–25% H,more preferably from about 3–18% H) or include other dopants indifferent embodiments of this invention, and/or may have a density of atleast 2.4 gms/cm³ in certain example instances.

FIGS. 3–4 illustrate an example ion source 25 which may be used toimplant C ions in layer 3 according to certain example embodiments ofthis invention. Ion source 25 includes gas/power inlet 26, anode 27,grounded cathode magnet portion 28, cathode magnet portion 29, andinsulators 30. A 3 kV (or other power supply amount) DC and/or AC powersupply may be used for source 25 in some embodiments. The voltagesdescribed above are provided between the anode 27 and the cathode 29 ofthe ion source proximate the electric gap near the racetrack shaped slitin the cathode. Ion beam source 25 is based upon a known gridless ionsource design. The linear source includes a linear shell (which is thecathode and may be grounded) inside of which lies a concentric anode(which is at a positive potential). This geometry of cathode-anode andmagnetic field 33 gives rise to a closed drift condition. The source canalso work in a reactive mode. The source may includes a metal housingwith a slit in a shape of a race track as shown in FIGS. 3–4, the hollowhousing being at ground potential in example instances. The anodeelectrode 27 is situated within the cathode body 28, 29 (thoughelectrically insulated) and is positioned just below the slit. The anode27 can be connected to a positive potential as high as 3,000 or morevolts (V) (or as otherwise needed for the varying ion energies usedherein). Both electrodes may be water cooled in certain embodiments. Oneor more feedstock or precursor gas (e.g., acetylene, other hydrocarbongas, or any other suitable gas) is/are fed through the cavity betweenthe anode and cathode (or alternatively may be otherwise provided at thesource).

Still referring to FIGS. 3–4, electrical energy cracks the gas(es) toproduce a plasma within the source 25. The ion beam emanating from theslit is approximately uniform in the longitudinal direction and has aGaussian profile in the transverse direction. Exemplary ions 34 in theion beam are shown in FIG. 3. A source as long as four meters may bemade, although sources of different lengths are anticipated in differentembodiments of this invention. Electron layer 35 completes the circuitthereby enabling the ion beam source to function properly. The ion beamsource of FIGS. 3–4 is merely exemplary. Thus, in alternativeembodiments of this invention, an ion beam source device or apparatus asdescribed and shown in the first three figures of U.S. Pat. No.6,002,208 (hereby incorporated herein by reference in its entirety) maybe used. Any other suitable type of ion source may also be used.

In certain embodiments, the oxycarbide may be heated during and/or afterthe ion beam treatment, from for example from about 100 to 650 degreesC. This heating may make the surface more hydrophilic, and/or to enhancethe formation of oxycarbides.

EXAMPLES

For purposes of example only, several examples were made and analyzed inaccordance with different embodiments of this invention. In each of thebelow-listed examples, an amorphous TiO₂ layer 3 approximately 220–230 Åthick was magnetron sputtered onto a 3 mm thick glass substrate 1. Then,each sample was passed beneath an ion source 25 at a rate of 100 inchesper minute, where the source 25 used acetylene gas to expel at least Cions toward the layer 3. The beam was incident on the layer 3 at anangle of about 90 degrees. In Example 1, the layers were deposited onthe tin side of the float glass substrate 1, whereas in Examples 2–4 thelayers were deposited on the air side (non-tin side) of the substrate 1.Processing for the implantation for each example is set forth below. Gasflows below are total gas flows of acetylene in units of sccm in thesource, and voltage is the anode/cathode voltage in source 25.

TABLE 1 IMPLANTATION PROCESSING FOR EXAMPLES Gas & Flow Voltage CurrentPressure Example 1: C₂H₂ 100 sccm 4,500 V 0.87 A 0.30 mTorr Example 2:C₂H₂ 100 sccm 3,000 V 0.79 A 0.32 mTorr Example 3: C₂H₂ 120 sccm 3,000 V1.01 A 0.35 mTorr Example 4: C₂H₂ 310 sccm 3,000 V 1.17 A 0.99 mTorr

Example 1 was analyzed via XPS, at two different locations illustratedin FIGS. 5 and 6. In the XPS analysis, 15 Å steps were used. FIG. 5 isan XPS graph illustrating the elements/components present in atomicamounts throughout the thickness of the layer system of Example 1 at afirst location on the substrate, where in the graph the vertical axisrepresents atomic percent while the horizontal axis represents the depthinto the coating from the exterior surface thereof in units of angstroms(Å) relative to sputtering of a silicon oxide layer as is known in theart. FIG. 6 is similar to FIG. 5, except that the data was measured at adifferent location on the Example 1 sample. The instrument used for themeasuring was a Physical Electronics Quantum 2000 Scanning XPS, and thex-ray source was monochromatic Al Kα. The analysis area was 0.2 mm by0.2 mm, and the take-off angle was 45 degrees. Sputter conditions usedfor the reference thickness were 1 keV Ar+, 2 mm×2 mm raster, ˜30 Å/minvs. SiO₂.

As shown in FIGS. 5–6, on the surface the proportion of C—O relative toC—C/C—H appears to be similar in both areas. The O1s spectra reflects amixture of metal oxides and hydroxide/organic. Moreover, it is notedthat the coating thickness appears to be smaller in the location of FIG.5 than in the location of FIG. 6 (the increase in Si content in FIGS.5–6 is indicative of the presence of the glass substrate under thecoating). The C1s spectra in the depth profile in FIG. 5 do not revealthe presence of TiC per se, rather it suggests an intermediate speciesof C in the matrix of TiO_(x) (i.e., titanium oxycarbide), possiblybonded to both Ti and O (again, titanium oxycarbide). Thus, the phrase“titanium oxycarbide” as used herein includes TiOC bonding, and alsosituations where C is provided in a matrix of TiO_(x) but need notnecessarily be bonded thereto.

Unfortunately, severe peak interference in the Ti2p spectra preventeddifferentiation of TiC and TiO, which have nearly the same bindingenergy; and also precluded differentiation of various oxidic states dueto Ti2p3 and Ti2p1 spectra interference. This leads us to use two labelsfor Ti, elemental Ti and TiO_(x)C_(y)/TiC. In FIG. 5, a significantproportion of Ti appears to be in elemental state near the glasssubstrate 1 interface, and not much TiC was observed judging from thelack of C—Ti peak in the C1s spectra. In contrast, C—Ti bonding wasindeed present in the C1s spectra in FIG. 6 and it peaked at about 50 Å.The intermediate species of C in the matrix of TiO_(x), as mentionedabove, was also present in the C1s spectra in FIG. 6. FIG. 6 alsoillustrates a higher TiO_(x)C_(y)/TiC concentration around 50 Å, andsignificant titanium oxycarbide in this respect all the way through thelayer 3, implying a fairly uniform distribution of the titaniumoxycarbide component. In FIG. 6, elemental Ti was present in the filmexcept for the top 50 Å. The film of Example 1 was also found to have avery low contact angle, which angle decreased upon exposure to visiblelight, and superior scratch resistance compared to titanium oxide.

FIG. 7 is a graph comparing Example 2 (TiO₂+C implant) vs. both a layerof only TiO₂ on a substrate and a layer of C implanted TiO₂ coated witha layer of DLC about 40 Å thick over the same. It can be seen that thecoated article of Example 2 had lower initial contact angle than eitherof the other two articles, which is advantageous in certain instances.Moreover, FIG. 7 illustrates that Example 2 was able to maintain a lowcontact angle for a longer period of time than were the other twosamples.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiment, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1. A method of making a coated article, the method comprising: providinga glass substrate; sputtering a layer comprising titanium oxide TiO_(x)(where x is from 1 to 3) on the substrate, thereby forming a sputteredlayer; and utilizing at least one ion source using anode-cathode voltageof at least about 1,500 V to cause at least carbon ions to be directedtoward the sputtered layer comprising titanium oxide so that at leastsome of the carbon ions are implanted into the sputtered layer to adepth of at least 25 Å below a surface of the sputtered layer, so that alayer comprising titanium oxycarbide is an outermost layer of a coatingof the coated article.
 2. The method of claim 1, wherein said carbonions are implanted into the sputtered layer so as to form asubstantially continuous layer comprising titanium oxycarbide proximatethe surface of the sputtered layer.
 3. The method of claim 1, whereinsaid ion source uses anode-cathode voltage of at least about 2,000 V tocause said carbon ions to be directed toward the sputtered layer.
 4. Themethod of claim 1, wherein said ion source uses anode-cathode voltage ofat least about 3,500 V to cause said carbon ions to be directed towardthe sputtered layer.
 5. The method of claim 1 wherein said ion sourceuses anode-cathode voltage sufficient to cause at least some of thecarbon ions directed toward the sputtered layer to have an ion energy ofat least about 200 eV per carbon ion.
 6. The method of claim 1, whereinsaid ion source uses anode-cathode voltage sufficient to cause at leastsome of the carbon ions directed toward the sputtered layer to have anion energy of at least about 375 eV per carbon ion.
 7. The method ofclaim 1, wherein said ion source uses anode-cathode voltage sufficientto cause at least some of the carbon ions directed toward the sputteredlayer to have an ion energy of at least about 500 eV per carbon ion. 8.The method of claim 1, wherein said ion source uses anode-cathodevoltage sufficient to cause at least some of the carbon ions directedtoward the sputtered layer to have an ion energy of at least about 625eV per carbon ion.
 9. The method of claim 1, wherein said ion sourceuses anode-cathode voltage sufficient to cause at least some of thecarbon ions to be implanted into the sputtered layer at a depth of atleast 50 Å below the surface of the sputtered layer.
 10. The method ofclaim 1, wherein said ion source uses anode-cathode voltage sufficientto cause at least some of the carbon ions to be implanted into thesputtered layer at a depth of at least 100 Å below the surface of thesputtered layer.
 11. The method of claim 1, wherein the coated articlehas a contact angle θ of no greater than about 20 degrees.
 12. Themethod of claim 1, wherein the coated article has a contact angle θ ofno greater than about 15 degrees.
 13. The method of claim 1, furthercomprising directing visible light toward the coated article whichvisible light causes a contact angle θ of the coated article todecrease.
 14. The method of claim 1, wherein at least a hydrocarbon gasis used in the ion source, so that at least carbon ions and hydrogenions are directed toward the sputtered layer in an ion beam.
 15. Themethod of claim 1, wherein at least one additional layer is provided onthe substrate between the sputtered layer comprising TiO_(x) and thesubstrate.
 16. The method of claim 1, wherein the layer comprisingtitanium oxide is amorphous.
 17. The method of claim 1, wherein thecoated article is a window.
 18. A method of making a coated article, themethod comprising: providing a substrate; sputtering a layer comprisingtitanium oxide on the substrate, thereby forming a sputtered layer;directing at least carbon ions toward the sputtered layer comprisingtitanium oxide, at least some of the carbon ions having an ion energy ofat least 200 eV per carbon ion so that at least some of the carbon ionsimplant in the sputtered layer thereby forming a layer comprisingtitanium oxycarbide which is an outermost layer of the resulting coatedarticle; and wherein at least some of the carbon ions implant into thesputtered layer to a depth of at least 25 Å below a surface of thesputtered layer.
 19. The method of claim 18, wherein said carbon ionsare implanted into the sputtered layer so as to form a substantiallycontinuous layer comprising titanium oxycarbide proximate a surface ofthe sputtered layer.
 20. The method of claim 18, further comprisingusing an ion source using anode-cathode voltage of at least about 2,000V in directing said carbon ions toward the sputtered layer.
 21. Themethod of claim 18, further comprising using an ion source usinganode-cathode voltage of at least about 3,500 V in directing said carbonions toward the sputtered layer.
 22. The method of claim 18, wherein atleast some of said carbon ions directed toward the sputtered layer havean ion energy of at least about 375 eV per carbon ion.
 23. The method ofclaim 18, wherein at least some of said carbon ions directed toward thesputtered layer have an ion energy of at least about 500 eV per carbonion.
 24. The method of claim 18, wherein at least some of said carbonions directed toward the sputtered layer have an ion energy of at leastabout 625 eV per carbon ion.
 25. The method of claim 18, wherein atleast some of the carbon ions implant into the sputtered layer to adepth of at least 50 Å below a surface of the sputtered layer.
 26. Themethod of claim 18, wherein an ion source uses anode-cathode voltagesufficient to cause at least some of the carbon ions to be implantedinto the sputtered layer at a depth of at least 100 Å below a surface ofthe sputtered layer.
 27. The method of claim 18, wherein the coatedarticle has a contact angle θ of no greater than about 20 degrees. 28.The method of claim 18, wherein the coated article has a contact angle θof no greater than about 15 degrees.
 29. The method of claim 18, furthercomprising directing visible light toward the coated article whichvisible light causes a contact angle θ of the coated article todecrease.
 30. The method of claim 18, wherein at least a hydrocarbon gasis used in the ion source, so that at least carbon ions and hydrogenions are directed toward the sputtered layer in an ion beam.
 31. Themethod of claim 18, wherein at least one additional layer is provided onthe substrate between the sputtered layer comprising titanium oxide andthe substrate.
 32. The method of claim 18, wherein the coated article isa window.
 33. A method of making a coated article, the methodcomprising: providing a substrate; forming a layer comprising a metaloxide on the substrate; directing at least carbon ions toward the layercomprising the metal oxide, at least some of the carbon ions having anion energy of at least 200 eV per carbon ion so that at least some ofthe carbon ions implant in the layer thereby forming a layer comprisingan oxycarbide which is an outermost layer of the resulting coatedarticle; and wherein at least some of the carbon ions implant into thelayer to a depth of at least 25 Å below a surface of the layer.
 34. Themethod of claim 33, wherein at least some of said carbon ions directedtoward the layer have an ion energy of at least about 375 eV per carbonion.
 35. The method of claim 33, wherein at least some of said carbonions directed toward the layer have an ion energy of at least about 500eV per carbon ion.
 36. The method of claim 33, wherein at least some ofsaid carbon ions directed toward the layer have an ion energy of atleast about 625 eV per carbon ion.
 37. The method of claim 33, whereinsaid metal comprises Ti.
 38. The method of claim 33, further comprisingheating the layer comprising the metal oxide in order to enhanceformation of oxycarbide.
 39. The method of claim 33, wherein said metalcomprises Ti.
 40. The method of claim 33, wherein the coated article isa window.
 41. A method of making a coated article, the methodcomprising: providing a glass substrate; sputtering a layer comprising ametal (M) oxide MO_(x) (where x is from 1 to 3) on the substrate,thereby forming a sputtered layer; and utilizing at least one ion sourceusing anode-cathode voltage of at least about 1,500 V to cause at leastcarbon ions to be directed toward the sputtered layer comprising themetal oxide so that at least some of the carbon ions are implanted intothe sputtered layer to a depth of at least 25 Å below a surface of thesputtered layer thereby forming a layer comprising oxycarbide; andwherein the oxycarbide is at an outermost portion of a coating of thecoated article so as to be exposed to surrounding atmosphere.
 42. Themethod of claim 41, wherein a heterojunction is formed at the interfacebetween the layer comprising oxycarbide and the layer comprising DLC.43. The method of claim 42, wherein when incident visible light hitscharge accumulated at the heterojunction, electron hole pairs form andcause contact angle θ to decrease.
 44. A method of making a coatedarticle, the method comprising: providing a substrate; forming a layercomprising a metal oxide on the substrate; directing at least carbonions toward the layer comprising the metal oxide, at least some of thecarbon ions having an ion energy sufficient so as to cause at least someof the carbon ions to implant in the layer to a depth of at least 25 Åbelow a surface of the layer and form a layer comprising an oxycarbide,wherein the oxycarbide is at an outermost portion of the coated articleand is exposed to surrounding atmosphere in the resulting coatedarticle.
 45. The method of claim 44, wherein the coated article is awindow.
 46. The method of claim 44, further comprising providing anadditional layer on the substrate between the substrate and the layercomprising the metal oxide.